Existing oil impervious devices used as drain plugs or barrier booms are good in stopping the flow of oil such as transformer or compressor oils but also significantly restrict the flow of water such as rain water. In the applications where catch pans or ponds are installed under the oil containing equipments, such as transformers and compressors, it is desirable to equip the drains of these catch pans or ponds with oil impervious devices to block any accidental oil leakage in to the surrounding ground. The existing oil impervious devices available for these applications are deficient in permitting the rain water from draining at a desirable rate which can cause water overflow as well as accidental oil overflow. Therefore, it is desirable to have oil impervious devices which can allow high rate of water flow through them while maintaining its oil impervious property.